Method of making nuts



NOV. 20, 1934. L. F AYER 1,981,594

METHOD OF MAKING NUTS Original Filed June '7, 1930 v 1554. Parselrroe/vsm Patented Nov. 20, 1934 UNITED STATES rare NT oFFi-cE METHOD OFMAKING NUTS Lee A. Frayer, Kent, Ohio, assignor to Roy H. Smith, Kent,Ohio 9 Claims.

This invention relates to a new method of making accurate, high qualitynut blanks, starting with rough oversize blanks and proceeding through aseries of operations to bring about a gradual reduction in the outerdimensions of the blanks and a compacting, smoothing and hardening ofthe metal thereof,as well as the formation of the blanks with a highdegree of precision. My method also involves the step of causing theblank to project from one of the reducing dies and machining it while soheld, the die being thus utilized as a work holding chuck of thegreatest accuracy. The application is a division of my copendingapplication Serial No. 459,656 filed June 7, 1930.

At the present time, nut blanks of the highest grade are usuallymachined out of bar stock. This method involves the expenditure ofconsiderable time, and wastes some little material because of the boringof the hole and because of the fact that the cutting tool for cuttingoff each blank must have width. 'The "greater bulk of nut blanks nowmanufactured, however, .are cold pressed out of strip metal. Here,:again, there is a waste of material which, is thecase of hexagonalnuts, runs in the neighborhood of 45% of the gross. Nuts manufactured inaccordance with my new method are of far better quality than those madefrom blanks pressed outof strip steel, and are equal, if not superior,in accuracy, strength, hardness and finish to nuts turned out of barstock. The waste of metal, however, is but 10% of the gross.

Accordingly, one of the objects of my invention is the provision of amethod of making nuts which shall practically eliminate material wasteand shall result in the formation of a nut of great precision, strength,hardness and fine finish.

Another object is the provision of a new method of making nuts fromrough blanks, which involves passing oversized blanks through a seriesof reducing dies.

A further object is the utilization of a reducing die as a chuck forholding the blank during a machining operation in order that thecentering of the machining tool with respect to the work may be accurateto the greatest possible degree.

In the accompanying drawing Ihave illustrated .certain apparatus whichmay be employed in carrying out the invention, and in addition haveshown the condition of the work-at variousstages of the method. 7

Figs. 1, 2 .and 3 are more or less diagrammatic views, showing some ofthe parts in vertical section, of apparatus which may be employedincarrying out my method.

Figs. 4 and 5 are elevational and sectional views respectively of arough blanksuch \as may -be employed in carrying out the invention.

Figs. 6 and 7 are elevational and sectional views respectively of ablank following the first reduction and countersinking steps of themethod.

Fig. 8 is a sectional View of the blank following the second reductionand countersinking step of the method, and

Figs. 9 and 10 are side and elevational-views respectively of a blanksubsequent-to the third reduction step and subsequent to ;a machiningoperation performed upon one face of the blank.

In accordance with the method of :my invention, the work acted upon mayconsist of rough hot-pressed blanks formedwith central openings, theblanks being of theiormil-lustratedin Figs.-4=and 5, although noattempthas been made in the illustration to show the roughnessand-inaccuracy to which these blanks may be i-subject. They are madesomewhat larger and somewhat thinner than the corresponding dimensionsof the finished article. In practice they may runas much asfifty-thousandths of-an inc-h oversize. In the drawing the blank used inthe method-before any operation is performed upon it, isma rked 10, andits opening is marked 11. This blank is brought into alignment with theopening of a reducing die 12. It is to be understood .thatthe termsreducing and reducing die, .as herein employed, shall be construed toexclude trimming and trimming die, respectively, or any dies oroperations which effect a :cutting .ofythe blank as distinguished from acompressing \or extruding of the same. A plunger l3, -is-then=.advanced,the pilot 14 on the forward end ef-the plunger entering the opening '11of :the ablank.

A conical neck ;15 between the pilot 14 and the plunger proper engagesthe blank-and carries it into the die opening. -Ti1e dimensions-of the,die opening are such -thatthe {blank isdrawndoyvn, reduced, orextruded. to a vmaterial extent,-=that=is so that its transversedimensions 81126 reduced, say twenty-thousandths of an inch,.-'and its(thickness accordingly increased to ta slight -extent. git the same timethe conical neck 15 produces .-a countersink in the blank, 133$indicated at 1,6 in the drawing. The pilot 14,-of (toured-preventsthe'opening in the blank from being reduced-by the inward pressure ofthe die. -E[ -he;|plunger is moved forward to approximately the positionillustrated in Fig. 1,- and then retracted, leaving the blank still ,inthe die, although;a portion of it may be exposed. The blank left in thedie by the preceding operation is thus forced out, and may be droppedinto a suitable receptacle or otherwise removed or disposed of. In thedrawing, the blank as it emerges from the die after this first step ofthe method is marked 17, and is shown in detail in Figs. 6 and '7.

In the second step of the method the partly formed blank 17 is forcedinto a second reducing die 18 by means of a second plunger 19 having apilot 20 and a conical neck 21 similar to the corresponding parts inFig. 1. The blank 17 is caused to enter the die with its countersink 16forward. The die 18 is smaller than the die 12, so as to bring about asecond reduction of the transverse dimensions of the blank by extrusionof metal. maybe in the neighborhood of twenty-thousandths of an inch. Inthe course of this operation the neck 21 of the plunger produces acountersink' 22 in the rear face of the blank. The blank resulting fromthis second step of the method is marked 23 in the drawing.

A third reduction step is illustrated in Fig. 3, wherein the die 24 isslightly smaller than the die 18. The difference in size in this casemay be somewhat less than before, or in the neighborhood often-thousandths of an inch. A third plunger 25, having a pilot 26 and aconical neck 27 is employed. through the die, approximately to theposition illustrated inFig. 3, and then the plunger is retracted, itbeing illustrated in this figure at a point in its movement ofwithdrawal. I

' While the blank is thus held in the die 24, preferably with itsforward face protruding somewhat beyond the face of the die, I performupon it some one or more machining operations. In the drawing I haveshown a head 28 mounted upon a shaft 29 which is supported in ballbearings 30 and 31, the shaft .beingarranged in alignment with the axisof the die. It is possible by careful workmanship to make this centeringoperation accurate to within one-thousandth of an inch. In the head Imount the machining tool or tools, which in the present instance consistof a rearner 32 and a cutter 33, the latter being adapted to face theend of the blank and turn off the outer corners, producing what is knownas a crown. Any suitable means may be employed for rotating theshaft 29and for moving the bearings 30 and 31 backward and forward to and awayfrom operative position.

' In the case illustrated these bearings are mounted in a sleeve 34which has a rack 35 on one side thereof that is in mesh with a pinion36, which may be rotated to move the sleeve forward and backward. On therear end of the shaft 29, beyond'the bearing 31, there is keyeda gear 37which meshes with a .wide faced gear 38 driven by any suitablepowermeans. Hence the shaft 29 rotates continuously and travels back andforth with the sleeve 34. The condition of the blank after it is pushedout of the die 24 by the next blank pushed into the die, is illustratedat 39 in Figs. 9 and 10, and the crown produced upon the blank by thecutter-33 is shown in these figures at 40.

Although I have shown a machining operation being performed upon theblank while held in one only of the three dies 12, 18, 24, it is quiteapparent that it is within the purview of the'invention to perform othermachining"operationswhile the blank is held in one or more of the otherdies, and if such an operation were to be performed while This secondreduction, for example,-

The blank is forced; nearly the blank was held or chucked in die 18, aswell as while held in die 24, it is apparent that both faces of theblank would be machined.

A fin may be extruded from the blank backwardly over one or moresurfaces of the plunger, since the latter necessarily fits looselyenough to move readily through the die. The feature of leaving a blankin the ,die and discharging it by moving a'succeeding blank against ithas an important advantage in this respect, that the fin so fact thatthe surface of the blank in engagement with the die is much greater inextent than its surface in engagement with the pilot, the blank isfirmly held against retraction when the plunger is withdrawn.

The reducing operations serve not only to bring the blank down toaccurate dimensions, but also to compact, harden, strengthen and smooththe metal, producing a nut blank of precision and fine finish which issuperior also in strength to blanks made by other methods. The formationof a blank by my process is also economical because of the fact thatwaste metal is reduced to a minimum. is

In the foregoing description I have necessarily gone somewhat intodetail in order to explain fully the particular embodiments of theapparatus herein illustrated, but I desire it to be understood that suchdetail disclosures are not to be construed as amounting to limitations,except as they may be included in the appended claims.

Having thus described my invention, I claim:

1. The method of forming with precision, hardening, strengthening andsmoothing a nut blank, which consists in slidingly advancing a rough nutblank through a series of progressively tapering dies and therebyperforming a series of successive die forging operations upon the roughblank, and

3. The method of finishing a nutblank, which consists in slidinglyadvancing a rough nutblank through a series of progressively taperingdies and thereby performing a series of successive die forgingoperations upon the rough blank while maintaining the hole in the blankcentral and of a predetermined diameter substantially, and thus reducingthe transverse dimensions of the blank step by step, whereby the metalof the blank is compacted, hardened and smoothed, and the blank isbroughtv down tOxDTBCiSlOII dimensions.

4. The method of forming nut blanks, which consists in slidinglyadvancing a rough nut blank through a series of progressively taperingdies and thereby performing a series of successive die forgingoperations upon each rough nut blank while maintaining the hole in theblank central and of a predetermined diameter substantially, and thusreducing its transverse dimensions step by step, whereby the metal ofthe blank is compacted, hardened and smoothed, and the blank is broughtdown to precision dimensions, and reaming the hole in the blank whilethe same is held by one of the dies.

5. The method of making nut blanks, which comprises die forging anoversized blank by pushing it part way through a forging die, performinga machining operation upon the blank while so held, and then completingthe travel of the blank through the die.

6. The method of making nut blanks, which comprises forging an oversizedblank by causing a plunger to force the blank part way through areducing die, Withdrawing the plunger, performing a machining operationupon the blank while so held, and then causing the plunger to force asecond blank part way through the die, thereby completing the travel ofthe first said blank through the die.

'7. The method of making nut blanks, which comprises forging anoversized blank by pushing it part way through a reducing die, whilemaintaining the hole in the blank central and of a predetermineddiameter substantially, reaming the hole in the blank while it is soheld, and then completing the travel of the blank through the die.

8. The method of making a nut blank, which consists in performing aseries of successive forging operations upon a rough oversized blank, bypushing the blank through reducing dies of successively smaller size,interrupting the travel of the blank in one of said dies, performing amachining operation upon the blank while it is so held by the die, andthereafter completing the travel of the blank through the die.

9. The method of making nut blanks, which comprises performing a seriesof forging operations upon a rough oversized blank by pushing it throughdies of successively smaller size, the reduction in the first die beinggreater than the reduction in the last die, interrupting the travel ofthe blank in the last die, machining the blank while so held in the lastdie, and completing the travel of the blank through the last die.

LEE A. PRAYER.

